The best is purely opinion. Different people look for different things from their keyboard. I personally only use IBM Model M keyboards with a Dvorak software overlay.
I absolutely hate "membrane style" keyboards. I used to have an old Hitachi keyboard that I liked a lot too, but it's been gone for about 10 years.
EDIT: as far as gaming goes, I mostly play WoW and Battlefield 2, but I've been using a Model M or some form of mechanical keyboard since I touched my first PC in the late 80s. (Well, technically, probably since 1984 when my Father bought an Apple 2e. As the keyboard for it was machanical as well.)